Doug McNaught <[EMAIL PROTECTED]> writes: > "data=writeback" means that no data is journaled, just metadata (which > is like XFS or Reiser). An fsync() call should still do what it > normally does, commit the writes to disk before returning. > "data=journal" journals all data and is the slowest and safest. > "data=ordered" writes out data blocks before committing a journal > transaction, which is faster than full data journaling (since data > doesn't get written twice) and almost as safe. "data=writeback" is > noted to keep obsolete data in the case of some crashes (since the > data may not have been written yet) but a completed fsync() should > ensure that the data is valid.
Thanks for the explanation. > So I guess I'd probably use data=ordered for an all-on-one-fs > installation, and data=writeback for a WAL-only drive. Actually I think the ideal thing for Postgres would be data=writeback for both data and WAL drives. We can handle loss of un-fsync'd data for ourselves in both cases. Of course, if you keep anything besides Postgres data files on a partition, you'd possibly want the more secure settings. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org